MOSCOW – After finishing the World Cup group phase as the top-scoring team, Belgium has every right to be confident, but forward Dries Mertens said Saturday the Red Devils will approach Japan with the appropriate respect.

Belgium’s nine goals — scored in big wins over Panama and Tunisia, and a 1-0 victory over England in its final preliminary match — saw it top Group G and set up a meeting with Japan, which squeaked into the round of 16 thanks to FIFA’s fair-play rules.

Japan may prove an easy kill on Monday in the southwestern Russian city of Rostov-on-Don, but Mertens pointed to the Samurai Blue’s performance against Colombia as a reason to be wary.

“I think they are doing well,” said the Napoli player. “They won against Colombia, so that is very important for us to take this (into account) and I think they played very good games.

“Against Poland, it was a little bit different, but they had a very strong group.”

Mertens admitted he had not paid too much attention to Japan’s matches so far because “I don’t like to watch so much soccer,” but he knows the Asian team’s big names, and knows they must be respected.

“I know some players. I have played against (Keisuke) Honda, (Yuto) Nagatomo. They are playing in big teams. So, I don’t forget it,” the 31-year-old said.

“We have a lot of respect for this team, and we don’t think we are going to win this one easily.”

When it comes to big names, however, Belgium can put Japan in the shade.

With four goals, Manchester United striker Lukaku trails only England’s Harry Kane in the race for the golden boot, while Hazard has netted two and Mertens one.

“With the quality of Romelu and Eden, we can create a great deal of danger,” said Mertens.

But when asked whether the attacking trio is the World Cup’s most feared, Mertens played the modesty card.

“I don’t know,” he said. “I think we are doing really well. We like to score a lot of goals. You have a lot of good front threes in every country. We want to do well, and we want to score a lot.”

Mertens’ teammate Adnan Januzaj made a big impact against England on his debut at this World Cup, outfoxing defender Danny Rose with pretty footwork before curling in the winner with his left foot.

Speaking to media in Moscow on Saturday, the Real Sociedad winger identified his former Manchester United teammate Shinji Kagawa as the Japanese player he considers the most significant threat.

“He is someone who has a lot of experience and someone who has played in a lot of big clubs,” Januzaj said of the Borussia Dortmund midfielder, who converted from the spot in Japan’s 2-1 win over Colombia.